1. Field of the Invention
The present invention relates to a mounting bracket assembly, for example, to secure an electronic instrument such as a speaker on a ceiling trim of an automotive vehicle.
2. Background Art
Recently, it has been proposed that a speaker is secured to a ceiling trim of a car cabin. Japanese Patent Application Laid-open No. 2002-144973 discloses a mounting bracket assembly for securing a speaker to a frame of a car. The frame holds a ceiling trim made of a synthetic resin material.
The mounting bracket assembly has a jack nut and a base engaged with the jack nut. The jack nut is press-fitted in a hole of the frame. The base secures a support pillar of the speaker. To secure the speaker on the ceiling trim, a part of the ceiling trim is removed to expose the hole so that the jack nut engages with the base.
However, it is not popular that a car has such a frame with a securing hole. Thus, another mounting bracket assembly made of a metal and hooked on a synthetic-resin-made ceiling trim has been proposed.
The mounting bracket assembly disclosed in the laid-open application is not suitable for securing speakers to various types of cars most of which have no holes in a ceiling trim frame to secure speakers.
Even when the ceiling trim has a securing hole, the hole is covered by the ceiling trim. Thus, it is necessary to remove a part of the ceiling trim for fitting the mounting bracket assembly to the frame. This tends to require a laborious process to secure a speaker on the frame.
Meanwhile, it is difficult to secure a comparatively heavy speaker on a ceiling trim. Because, the ceiling trim is weak in mechanical strength. Thus, only a comparatively small speaker can be fitted on the ceiling trim.
In view of the above-mentioned situation, an object of the present invention is to provide a mounting bracket assembly for fitting a comparatively large electronic instrument such as a larger speaker to trims of various types of automotive vehicles.